The invention relates to a laundry dryer and a method for cleaning of a filter of a laundry dryer.
In laundry dryers such as tumble dryers or washer-dryers, the use of filters for cleaning the process air is known. In tumble dryers such a filter is arranged as a fluff filter in a process air channel leading away from the drum housing. When laundry is dried in a laundry drum within the drum housing, matter, in particular fluff, is extracted from the laundry with the process air as the process medium, and carried away with the process air in the process air channel. The filter serves to filter such fluff out of the process air, so that the fluff is not able to reach a condenser for drying of the process air and become deposited thereupon. This would impair an efficiency level of the condenser. Until now it has been possible to remove filters of this type and then manually clean them, in order to remove fluff adhering to the filter.
A dryer for drying laundry by means of a stream of air is known from patent specifications EP 1 788 140 A1, EP 1 788 141 A2 and EP 1 788 141 A2. A filter for filtering fluff out of a stream of air in the process air guide is arranged in the dryer in the region of an end plate, which filter forms a first fluff filter. By means of a scraper, fluff collecting on the filter in the process air guide is wiped off the filter fabric of the fluff filter and stored in a container arranged adjacent to the scraper and the filter. The scraper and the container thus form, together with further components, a first cleaning device. The container is, though, relatively small in dimensions, as a result of the constructional space available in the region of the scraper. The fluff from around 7 to 10 drying processes can be collected therein. As the fluff is stored in a dry state, it takes up a relatively large volume. On the one hand in the case of this dryer accessibility to the collecting container is limited, and on the other hand the collecting volume is restricted through its arrangement in a zone of the dryer which is of limited dimensions, giving rise to a relatively frequent maintenance interval for disposal of the fluff from the container. The dryer furthermore has a heater as a heat source and an air-to-air heat exchanger as a heat sink in the process air guide.
US 2006/0123854 A1 relates to a washing machine, which is combined with a dryer. A housing is provided for in the washing machine, a trough is built into the housing, a venting hose is attached to an outer surface of the trough, a fluff filter arrangement has an end connected with the venting hose, in order to remove fluff from the air, which is emitted from the trough, and a venting line is connected with the other end of the fluff filter arrangement. The fluff filter arrangement collects fluff from the through-flowing moist air. The collected fluff is deposited on a filter of the fluff filter arrangement, and the deposit of fluff is removed by means of the injection of water from a water inlet line onto the filter from the front. The removed fluff is directed through the venting hose into the trough. The fluff filter arrangement built into the housing is inclined at a predetermined angle in the direction of the front of the washing machine, so that a user can easily remove the filter unit from the front of the washing machine and can repair the fluff filter arrangement.
WO 2009/015919 A1 relates to an arrangement for the automatic cleaning of air filters, in particular of such as are designed for use in applications such as the drying circuit of a washing machine for clothing, which works according to a heat pump principle, having at least one sharp-stream injection nozzle for the injection of fluid and at least one air filter unit, wherein the liquid injection nozzle is arranged in such a way that it is a position to move relative to a fixed frame, wherein the relative movement is brought about by means of at least one actuator means connected therewith. The air filter unit and/or the liquid injection nozzle can be connected with the frame by means of a four-bar linkage. Cleaning here presupposes the movement of the air filter unit relative to the injection nozzle, necessitating a high degree of equipment-related effort and large space requirements.